Milling machines are very common pieces of equipment in a machine shop. A Bridgeport.TM. 3-Horsepower milling machine having a 10".times.54" worktable is a typical example. Traditional milling machines have a worktable which can be moved in three dimensions. The vertical position of the worktable is generally set at a height that is appropriate for a particular workpiece and is changed less often than the worktable position in the two dimensions of the horizontal plane. All of the three dimensional position adjustments are made by the manipulation of cranks.
The worktable of a milling machine is comparatively long in the lateral direction (left-right) and short in the direction from the machine pedestal to the operator (in-out). When the milling machine worktable is centered in the lateral direction with respect to the machine pedestal, the distance from the center to the end of the worktable is about equal to the length of an average operator's arm. The two cranks which are used to move the table laterally are located on the lateral ends of the worktable, and are somewhat difficult for the operator to reach. When the worktable is moved out of center, one of the lateral movement cranks is farther from center and the other is closer; if the one which is farther is the one manipulated by the operator with his or her dominant hand, the difficulty of reach becomes troublesome.
Some milling machines have servomotors for driving the lateral table moving cranks. While helpful in many instances, a motorized control is less sensitive than a manual control and tends to be expensive.
Thus, a milling machine having at least one easily reached lateral movement crank would be a benefit to the machine user. In addition to improving newly produced milling machines, a retrofit adaptation would be equally useful because of the large number of milling machines in existence.
It is therefore an object of this invention to provide a milling machine with a crank for lateral movement of the machine table which resides within relatively easy reach of the machine operator.
It is a further object of this invention to provide an adapter to be added to an existing milling machine which will reposition at least one of the cranks for lateral movement of the machine table so that it is within relatively easy reach of the machine operator.
Other objects and advantages will be more fully apparent from the following disclosure and appended claims.